United States
       Environmental Protection
       Agency
Office of Air Quality
Planning and Standards
Research Triangle Park NC 27711
EPA-450/4-90-013
December 1990
       Air
       USER'S GUIDE

               TO

          TSCREEN

A MODEL FOR SCREENING TOXIC
               AIR
 POLLUTANT CONCENTRATIONS

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                                    EPA-450/4-90-013
          USER'S GUIDE
                    TO
              TSCREEN

A MODEL FOR SCREENING Toxic AIR
    POLLUTANT CONCENTRATIONS
                      By

           Kevin Stroupe, Steve Boone & Calvin Thames
              Pacific Environmental Services, Inc.
                 Durham, NC 27707


               EPA Contract No. 68-02-4464


           EPA Technical Representative: Jawad S. Touma
                    U.S. Environmental Protection Agency
                    Region 5, Library (PL-1"J)
                    77 West Jackson Boulevard, Uiii Floor
                    Chicago, IL  60604-3590

           Office Of Air Quality Planning And Standards
                Office Of Air And Radiation
             U. S. Environmental Protection Agency
              Research Triangle Park, NC 27711

                   December 1990

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                                   Disclaimer

This report has been reviewed by the Office of Air Quality Planning And Standards, U.S.
Environmental Protection Agency, and has been approved for publication as received from
the contractor.  Approval does not signify that the contents necessarily reflect the views
and policies of the Agency, neither does mention of trade names or commercial products
constitute endorsement or recommendation for use.
                                EPA-450/4-90-013
                                        n

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                        TABLE OF CONTENTS




                                                               Page




1.0  INTRODUCTION                                                1




2.0  GETTING STARTED                                              2




3.0  EXAMPLE SCENARIO                                             5




4.0  ENTER/EDIT SCENARIO DATA                                     17




5.0  HELP SYSTEM                                                  27




6.0  ERROR HANDLING                                              28




7.0  SYSTEM FLOW                                                 29




8.0  BACKING UP DATA                                              30




9.0  NOTES ON COMPILING THE SOURCE CODE                           31
                                111

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                              1.0  INTRODUCTION

      The Techniques Evaluation Section (TES) of the Office of Air Quality Planning and
Standards (OAQPS) provides guidance and recommendations on  the application of air
quality models for a variety of purposes. The continuing involvement in the Superfund
toxic/hazardous pollutant impact activities has created a need for easy to use air quality
screening modeling techniques. The EPA has developed the  document "A Workbook Of
Screening Techniques For Assessing Impacts of Toxic Air Pollutants", EPA-450/4-88-009,
that can serve this purpose based on a set of logical and mathematical procedures. Pacific
Environmental Services, Inc. (PES) has developed TSCREEN, A Model for Screening Toxic
Air Pollutant Concentrations.  This computer program implements the procedures in the
workbook and is a screening model that can be easily used by State and local agencies.

      To correctly analyze toxic emissions and their subsequent dispersion from one  of
many different types of possible releases from Superfund sites, the computer program
TSCREEN should be used in conjunction with the workbook.  With the use of these tools
one can determine the type of release and what steps  are to be followed so that the release
can be simulated via an applicable computer model and then the dispersion characteristics
and pollutant concentrations of the resulting plume calculated. The air toxics dispersion
screening models imbedded  in TSCREEN that are  used for the  various scenarios are
SCREEN, RVD, and PUFF. Using TSCREEN, a particular release scenario is selected via
input parameters, and TSCREEN automatically selects and executes  the  appropriate
dispersion model to simulate that  scenario.  The model to be used and the appropriate
worst case meteorological conditions are automatically selected based on criteria given  in
the workbook. TSCREEN has a front-end control program to the models that also provides,
by use of interactive menus and data entry screen, the same steps as the workbook. The
correct release scenario  and associated characteristics of a  toxic  emissions release are
selected with the help of on-screen text; graphics and data input is performed in a full-
screen edit mode. TSCREEN saves the input data for each release scenario to  a file that
can be retrieved and later edited or executed. TSCREEN also  provided a method of easily
viewing and saving the modeling results for each modeled scenario.

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                            2.0 GETTING STARTED

Hardware Requirements

      TSCREEN  is an  IBM PC-based software application  written and  compiled  in
Microsoft™ BASIC Version 7.1 and Microsoft™ C Version 5.1.  The program requires 500
kilobytes (K) of free Random Access Memory (RAM). Although TSCREEN may operate
with certain memory resident programs installed, no attempt has  been made to test its
operation against all memory resident programs available today. If problems occur while
TSCREEN and memory  resident programs are running simultaneous, try removing the
memory resident programs from memory and reexecute TSCREEN. The TSCREEN program
files consisting of all executables and help related programs occupy about 1.5 megabytes
(MB) of disk space. The source code, executables and a WordPerfect™ formatted manual
require 2.3 MB of disk space. As scenario files are created, the hard disk space needed will
increase. To install TSCREEN on hard disk systems make sure there is at least 1.5 MB  of
free disk space available to load and execute the program.

      The computer running TSCREEN must be booted with the CONFIG.SYS file in the
root directory of the boot up disk containing the following parameters in order to execute
properly:

      Files = 20
      Buffers = 22

If the CONFIG.SYS file already has these statements with higher values assigned, then no
modification is necessary, otherwise either add the needed statements or increase their
value to that of the example and reboot the computer.

      The files required to run TSCREEN are as follows:

      AVETIME.EXE - The averaging time program
      CHEMBASE.EXE - The chemical database program
      CHEMBASE.DAT  - The chemical parameter look-up database
      CHEMBASE.IDX - The chemical database index file
      CHEMHELP.HLP - The chemical database help file
      CHEMHELP.IDX - The chemical database help index file
      CHEMHELP.NDX  - The chemical database help index file (link)
      ERHANDLE.EXE - The error handling program
      ERMSG.DAT - The error message file
      GLOSS.HLP - The glossary file
      GLOSS.NDX - The glossary file index (link)
      GRAF.EXE - The graph device selection program
      GRAPH.EXE - The graph generating program
      HELPSYS.EXE - The help system program

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      PCXHELP.EXE - The graphics help program
      PUFFTS.EXE - The PUFF model
      RVDTS.EXE - The RVD model
      SCREENTS.EXE - The SCREEN model
      TSCREEN.EXE - The controlling program
      TSCREEN.HLP - The graphics help screen (text)
      TSCREEN.PCL - The graphics help screen (graphics)
      TSHELP.NDX - The help file index (link)
      TSHELP.HLP - The help file
      TSHELP.IDX - The help system index
      TSMAIN.EXE - The scenarios and model input program
      VFONT101.FNT - The graph font file
      VIEW.EXE - The model output viewer program

As TSCREEN scenarios are entered, the data  are automatically saved in files using the
following naming convention:

      *.TSN - Scenario data files are RUN00001.TSN to RUN30000.TSN

First Time Installation

      The complete package occupies a single 5l/4 inch, double-sided, high-density diskette.
TSCREEN must be installed on a hard disk in order to run. To install TSCREEN on a hard
disk, check the available disk space by running the DOS program CHKDSK. To check to
see if the DOS programs are  accessible from the PATH setting simply type:

      PATH

If the DOS sub-directory or sub-directories containing the DOS files is listed the type:

      CHKDSK

at the hard disk prompt where TSCREEN is to be installed.  If not, read your DOS manual
to understand what you have to do to run CHKDSK.  Check to make sure there is at least
1.5 MB of available disk space. If there is enough free disk space, then create a TSCREEN
sub-directory from the root directory of the hard drive on which TSCREEN will be installed.
The command to create a TSCREEN sub-directory off the main or root directory is:

      CD\
      MD TSCREEN

Once the sub-directory is created, insert the TSCREEN diskette in the high-density drive of
the computer (usually the A drive on IBM AT-type machines) and copy the files from the
diskette to the sub-directory  by typing the command:

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      COPY A:*.* X:\TSCREEN

where X is the letter designation of the drive which TSCREEN is to be installed (where the
sub-directory was created). Once the files are copied, the installation is complete. To start
TSCREEN simply change the sub-directory by typing the command:

      CD TSCREEN

Then, at the hard disk prompt where TSCREEN was installed, type:

      TSCREEN

to start the  program.

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                            3.0 EXAMPLE SCENARIO

      An example TSCREEN session is demonstrated in this section. For more information
on the scenarios in TSCREEN, the document, "A Workbook Of Screening Techniques For
Assessing Impacts OF Toxic Air Pollutants", EPA-450/4-99-009, should be referred to and
used as an accompanying guide with this program.

Title Screen

      Upon starting the program a title screen will appear as shown in Figure 1.

                                   FIGURE 1.
                                T  S  C R E  N

           A Model for Screening  Toxic Air Pollutant -Concentrations

                        Version 1.0      December 1990
        For Questions Contact:
   Jawad S. Touma, Project Officer
   US EPA, OAQPS, TSD (MD-14)
   Source Receptor Analysis  Branch
   Research Triangle Park, NC   27711
   (919) 541-5381
           Developed by:
Pacific Environmental Services,
3708 Mayfair Street, Suite  202
Durham, NC  27707
(919) 493-3536
Inc.
                             Press any key to begin.
Selection Windows
      After pressing a key, the first selection window will appear to allow the selection
of Initial Form of Release, access and retrieval of previously entered and saved sessions or
accessing/updating of the chemical database. An example of this screen is shown in
Figure 2.

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                                    FIGURE 2.
                     C  Initial  Form of Release J-
                       A«  Patfci.culat:e Matter-
                      B.  Gaseous

                      C.  Liquid

                      D.  Access File of Previous Scenario

                      E.  Access Chemical Database

                      Up   Down  /Letter=Select
                      Help            Exit TSCREEN
TSCREEN has help available at each point in the system, activated by pressing the Fl key.
An example of pressing the Fl key from the first selection window (Initial Form of Release)
is shown in Figure 3.
                                    FIGURE 3.
                  I—[  Initial Form of Release  ]-
                                                                          TH
  Particulate Matter
  A  Particulate Matter type rjti'4:£se is any solid material
  such  as particles, dust, or ash.
        :
  Gaseous
  A Gaseous type release is any material in a vapor  form
  such as sulfur dioxide, volatile organics, etc.
<||>List of Available KeysList of Highlighted PhrasesUp/DownExit
The user can also see the help screen for the other parameters.  Please see Section 5.0 for
a detailed discussion on the use of the help system. Once a selection is made from the first

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menu by using the arrow keys to highlight the desired release type and pressing the Enter
key (point and shoot) or by directly pressing the letter key to the left of the desired release
type, a second selection window will appear unique to the selection made from the first
selection window. For example if 'A. Particulate Matter" is selected from the first selection
window, a second selection window 'Particulate Matter Release Type' will appear as shown
in Figure 4.

                                    FIGURE 4.
                   [Particulate Matter  Release Types J
                                 Vents                   '
                     B.  Fugitive/Windblown Dust Emissions

                     C.  Ducting/Connector Failures

                     Up   Down     /Letter=Select
                     Help  Previous Menu   Abort
The  selections in this second menu of release types are specific to the  Initial Form of
Release selected from the first selection window. From this point selections can be made
by point and shoot, direct selection or help can be accessed by pressing the Fl key. The
user could also return to the previous selection window by pressing the F9 key. At the
second selection window level, graphics type help is available for computers with Hercules,
CGA, EGA or VGA type monitors and video cards. Otherwise help text appears without
graphics. An example of this graphics help is shown  in Figure 5.

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                                    FIGURE 5.
                               STACK RELEASES OF PARTICLES
  Similar Releases:   Continuous emissions of particulate Hatter fron vertical
  stacks and pipes OP conventional points sources and sone process vents  when
  enission flow rates and temperature are known,  Conkstion sources and  chemical
  reactors are typical  enission sources that exit polluntants through stacks,
  These releases Hay also be  due  to a process failure such as a rupture disk
  release or failure of control equipnent,


  PRESS Esc TO EXIT HELP     t FOR PREUIOUS HELP SCREEN     I TOR NEXT HELP SCREEN
These graphics help screens can be scrolled through to aid the user in selecting the desired
release type. Once the desired release type is viewed, pressing the Esc key will return the
highlighted bar to the selection that matches the help screen.


    Once a release type is selected  from the second selection window, a third  selection
window will appear which allows for the selection of Continuous or Instantaneous Release
Duration as shown in Figure 6.


                                    FIGURE 6.
                   [Release Duration ]-
                     B.   Instantaneous
                     Up   Down    /Letter=Select

                     Help  Previous  Menu   Abort
                                         8

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Data Entry Screens

    Once the selection is made from this third selection window, unique data entry screens
will appear for the selected scenario.   These screens  will guide  the  user  through
calculations that will select the appropriate dispersion model based on the data  entered.
For example, some of the screens calculate gas densities and others help calculate emission
rates.  In this example, the SCREEN model has now been selected based on user input.
Data entry  screens for this example are shown in Figures 7,  8, and 9.

                                   FIGURE 7.

 [ Continuous  Particulate  Matter Releases from Stacks - Scenario 4.1.1  ] -
    Based  on user  input, SCREEN model has been selected.

    SCREEN MODEL INPUTS -  Page 1 of 3
    Enter  a. unicjue title for this data's model run:
                       Release from Remedial;. Incineration
    RELEASE PARAMETERS
                                         Release Rate  (Q) ->  120       g/s
                                            Exit Velocity ->  5 ;        m/s
                              Release Height above Ground ->  20        m
                                Diameter at Release Point ->  Iv5       m
                     Temperature of the Material Released ->  320       °K
    AMBIENT  PARAMETERS
                                      Ambient Temperature ->  293       °K
    $di£     «F9S» Previous Screen     xNext Screen       Abort

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                                   FIGURE 8.

 [  Continuous Particulate Matter Releases  from  Stacks  -  Scenario 4.1.1 ]

  SCREEN MODEL INPUTS - Page 2 of  3

  BUILDING PARAMETERS
                Building Height  (enter  0  if  no  building)  ->  25       m
                   Building Minimum Horizontal  Dimension ->  20       m
                   Building Maximum Horizontal  Dimension ->  45       m

  FENCELINE DISTANCE
   Enter the distance from the base of  the stack  to  the
                                          plant  fenceline ->  100      m

  URBAN/RURAL CLASSIFICATION
                         Enter 1 for Urban - 2  for Rural ->  2

  RECEPTOR LOCATIONS
     Do you have specific locations where you would  like
         pollutant concentrations  to be calculated  (Y/N)  ->  Y
                  Previous Screen       Ne:xt" Screen      Abort
Note that the selected SCREEN program automatically calculates concentrations for many
receptors.  If the user selects V for the last entry, pressing F10 will advance TSCREEN to
the next page and allow the user to enter specified distances of interest that will be added
to the automatic receptors.   If the user enters  'N', SCREEN is executed with only the
automatic number of receptors.
                                      10

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                                    FIGURE 9.
-[ Continuous Particulate Matter Releases from Stacks - Scenario 4.1.1 ] 	
SCREEN MODEL INPUTS - Page 3 of 3
RECEPTOR LOCATIONS: Enter (up to 30) distances from
the source at which concentrations should be calculated.
Enter a blank after the
Distance from
Source (meters)
1 1GO fence
2 US
3 .!§•&' '"
4 2$9
5
6
7
8
9
10
„ iRun Model  Abort
In Figure 9, the first distance is the fenceline distance specified on the previous page. This
distance will appear automatically. All subsequent distances entered must be greater than
the fenceline distance. After pressing F10, the SCREEN model is executed. As the program
executes the user is shown what percent of the program is complete.
                                       11

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Averaging times

    The default averaging time in the SCREEN model is 1 hour.  If the  SCREEN model is
used and the release is a point source, the maximum concentration can be calculated for
additional averaging times selected from the menu shown in Figure 10.

                                  FIGURE 10.
                    -[ Averaging Times  ]	
                      The  default  averaging time is 1 hour.
                         For  additional  averaging times,
                        select one  or more from below. .  .

                                *  15 Minutes
                                   30 Minutes
                                *   3 Hours
                                *   8 Hours
                                *  24 Hours       :'.  .  : .

                          Help       Up  Down
                         /  Mark/Unmark Time
                             Select  Marked Times
                            Abort  Without Selection
Averaging times can be selected by pressing the Enter key or the Space bar to mark the
averaging time with an asterisk. In Figure 10, concentrations for a 15 minute, 3 hour, 8
hour, and 24 hour averaging times will be calculated. After all of the desired averaging
times have been selected, press F5 to proceed. The estimated concentrations for the new
averaging times will appear at the end of the model output.

Model Output

    When the model has completed execution, the output will be presented on the screen.
TSCREEN does not calculate concentrations in complex terrain or for elevated receptors.
An example  of a model's output is shown in Figure 11.  The user can scroll through the
model output by using the various keys shown. The user can also graph, print or save the
entire output to a file.  The instructions for the keys used in viewing the model output are
explained in Section 4.0 ENTER/EDIT SCENARIO DATA.
                                       12

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                                 FIGURE 11.
[  MODEL OUTPUT ]-
 1
-[ Top Row: 1  Left Column: 1  Length:  158  ]-
                                                07-11-
                                                12:46:
   *** SCREEN-1.1 MODEL RUN ***
   *** VERSION DATED  88300 ***

  Particulate Stack Release from Remedial Incineration

  SIMPLE TERRAIN  INPUTS:
     SOURCE TYPE            =    POINT
     EMISSION RATE (G/S)    =    120.0
     STACK HEIGHT (M)        =    20.00
     STK INSIDE DIAM (M)    =     1.50
     STK EXIT VELOCITY (M/S)=     5.00
     STK GAS EXIT TEMP (K)   =   320.00
     AMBIENT AIR TEMP (K)    =   293.00
     RECEPTOR HEIGHT (M)    =      .00
     IOPT (1=URB,2=RUR)     =     2
     BUILDING HEIGHT (M)    =    25.00
     MIN HORIZ BLDG DIM (M) =    20.00
     MAX HORIZ BLDG DIM (M) =    45.00
    Alt,
 Graph
 

Print , <-*•>, , , , Save to File Exit 13


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Graph

      If the Graph option is selected, a plot of the concentrations vs distances will be
drawn. The following window will appear first as shown in Figure 12.

                                  FIGURE 12.
              -[Graphics  -  Distance ]-
                  Enter Maximum Distance for Graph -> 10.
                        KM
                          Accept Entered Distance
                      Help                Use 50 KM
Once a distance has been specified the following menu will appear as shown in Figure 13.

                                  FIGURE 13.
MX
MX
[Graphics - Main Menu
  iL   screen
      EPSON FX,
      EPSON FX,
      EPSON LQ
      EPSON LQ
      NEC Pinwriter
      NEC Pinwriter
      OKIDATA
      OKIDATA
      HP LaserJet
      HP LaserJet
                      B.
                      C.
                      D.
                      E.
                      F.
                      G.
                      H.
                      I.
                      J.
                      K.
                      L.
                      M.
                      O.
                      N.
                Draft Quality
                High Quality
                Draft Quality
                High Quality
                Draft Quality
                High Quality
                Draft Quality
                High Quality
                Draft Quality
                High Quality
Hewlett-Packard plotter
Houston Instruments plotter
Change Distance for Graph
Save Graph to File
                      Up  Down
                      Help
  /Letter=Select
  Exit Graphics
                                      14

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From this menu the output device for the graph is selected.  Note that if your computer
does not have the ability to display graphics, the option 'A. Screen' will not be on this
menu. If a printer is selected then the output device is LPT1.  If a plotter if selected then
the output device is COM1. Before printing the graph, be sure that the printer is connected
and online.   After  exiting from the Graphics menu the user is returned  to the model
output.  Consult your printer's user's  manual to determine which of the above printers is
compatible with your printer.

      If 'N.  Save Graph to File' is chosen the window shown in Figure 14 will appear.
If you chose to save the graph's data, then the graph can be generated at a later time using
the GRAF  program.  To  generate an  old graph, type GRAF < graph filename >  from  the
DOS command line and then the window in Figure 12 will appear followed by the menu
shown in Figure 13.

                                   FIGURE 14.
          -[Graphics - Save]-
                Enter a unique name for this graph
                         Accept Entered File  Name
                   Help           Exit Without Saving
       If you are using a plotter, the DOS MODE command should be used to configure
your computer's communications port to correctly match the communications settings of
the plotter. For example, the Hewlett-Packard 7475A plotter has a set of switches located
on the back of the plotter which allows you to set the communications parameters.  A
common setting for these switches is shown in Figure 15.
                                       15

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                                   FIGURE 15.
                           S2  SI Y  US A3 B4 B3  B2  Bl
The DOS MODE command which should be used to correspond to these settings is:

MODE COM1:96,E,7,1

This command sets serial port 1 (COM1) to 9600 baud with even parity, seven data bits,
and 1 stop bit.

       Each plotter has unique methods of setting the communications parameters. You
should use the plotter's manual for the plotter configuration in conjunction with your DOS
manual's explanation on the use of the MODE command to be certain that your computer
and plotter are configured correctly.

       Once a selection is made, an example of the graph is shown in Figure 16.
                                   FIGURE 16.
                                i CU I Ot6  Stack
          "e72
           ^> 64
           ~ 56
          n
           2 48
           x

           232
           a 24

           i16
           o
           Z  8
           O
                !Fence line
0.0    0.5   1.0    1.5   2.0    2.5   10   15    4.0
                                                               4.5
                                   DISTANCE (km)
                          concentration 7.156E*I504 nicro^rarasAxbic neter at 0.100 km
                                  Press any key to continue
                                        16

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                       4.0  ENTER/EDIT SCENARIO DATA

      This section provides a description of the use of the various keys and data entry
procedures.

Data Fields

      A typical data entry screen is shown in Figure 17.

                                  FIGURE 17.
 -[Two Phase Relief Valve Discharges - Scenario 4.13]-

    SOURCE PARAMETERS - Page 1 of 3

    Enter• a uniquei title for this data's model run:
    FLASHED LIQUID FRACTION
    Enter the Percent of Liquid Flashed to Vapor  (F),  if  unknown
     enter the boxed variables below to calculate  ->-....      %
          Specific Heat at Constant Pressure  (Cp) ->
                  Latent Heat of Vaporization  (L) ->
       Storage or Line Temperature of Liquid  (Ts) ->
     Boiling Temperature at Ambient Pressure  (Tb) ->
                                              cal/g-mole  K
                                              cal/g-mole
                                              °K
                                              °K
    Help
 Calculator
 Previous Screen
 Abort
Commands active while editing data fields include:

Fl - Help on current field or chemical database, depending on field
F3 - Calculator
F9 - Return to previous screen
Esc - Abort entry and return to primary selection window
                                      17

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The keys that can be used for editing while in the highlighted data entry fields are as
follows:

Insert or Ins - toggle insert/overwrite mode (cursor changes size)
Delete or Del - delete character at cursor position
left arrow - move cursor left one character
right arrow - move cursor right one character
Control key and left arrow - move cursor left one word
Control key and right arrow - move cursor right one word
Backspace - move cursor back one character and delete character
Home - move cursor to beginning of data in field
End - move cursor to end of data in field
Control key and End key - delete data from cursor to end of field
Valid entry into numeric fields are numbers, minus signs(-), plus signs(+), a decimal(.),
and the letter E or e to stand for scientific notation (6.02E026 = 6.02e026 = 6.02E + 26
= 6.02e+26 = 6.02 x 1026).

Titles

   An important data field in TSCREEN for rerunning old scenarios is the 'Enter a unique
title for this data's model run:' field. This field should contain a unique title for each run.
Several ways to make the title unique are to give the facility name or add example 1,
example 2, etc, or the date and time to the title.  This is helpful when the selection 'D.
Access File of Previous Scenario ' option is used from the first selection window. The 'File
Name  Description' window will appear allowing the user to view the file names and titles
of all previously run scenarios.  A previous scenario may be selected to either run again or
update the data for another run. This window is shown in Figure 18. This title will also
appear on the  graph. However, only the first 42 characters of the title will be appear as
the title on the graph.
                                       18

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                                   FIGURE 18.
       •{File Name   Description]
                      Johnson Wi4$et Company
         RUN00002.TSN Dust  Ejection Number 2 6/20/90
         RUN00003.TSN Cent.  Part.  Stack Release-Power Plant-6/20/90
                S«Ia  Exit/no  selection
                one line     Op  oixe- page    Top of list
         fcown <»je linfc  <£5jJ3n> Oowft one page    Bottom  of list


   From  this window a previous scenario's data  can be reloaded  by  highlighting that
scenario's title  and pressing  the  Enter key.   The selection will take  the  user  to  the
beginning and the first selection window will reappear with the highlighted bar  on the
'Initial Form of Release' of the selected scenario.  By pressing the  Enter key again the
second selection window will  appear with the highlighted bar on the preselected 'Release
Type'.  By continuing to pressing the Enter key, the third selection window and the data
entry screens of the scenario are displayed with  the data fields filled  with the  loaded
scenario's data.  Selections can be changed at any point, but changing the selections on the
selection windows will cause the retrieved data to  be lost until it again  selected from the
'File Name  Description' window.
Calculated Fields

    Some of the data entry screens have fields that can be input directly or calculated
automatically from certain other parameters. The alternative parameters will be located
inside a box directly below the unknown parameter.  Figure 19 shows an example of a
calculated field where the percent liquid flashed to vapor is not known. Enter or the < j >
can be pressed and the data fields in the box below the percent liquid flashed to vapor field
can be completed. Once all entries are completed and Enter pressed, the percent liquid
flashed to vapor will automatically be calculated and will appear in the field above the box.
However, if the screen is reedited  and the  calculated  field is changed  then  the  other
parameter fields making up the calculated value will be blanked out.  If the percent liquid
flashed to vapor is known it can be entered directly and the program will automatically
skip over the parameter fields in the box.
                                        19

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                                   FIGURE 19.

 [Two Phase Relief  Valve Discharges - Scenario  4.13]	

    SOURCE PARAMETERS - Page 1 of 3

    Enter a unigue  title for this data's model  run:
    fh« Johnson Widget Company JtonQOI

    FLASHED LIQUID  FRACTION
    Enter the  Percent of Liquid Flashed to Vapor  (F),  if unknown
     enter the boxed variables below to calculate ->  20       %
Specific Heat at Constant Pressure (Cp) ->
Latent Heat of Vaporization (L) ->
Storage or Line Temperature of Liquid (Ts) ->
Boiling Temperature at Ambient Pressure (Tb) ->
2.0.0. :
100
400
390
cal/g-mole
cal/g-mole
°K
°K
°K



                   Previous Screeh •  •/'.: Next Screen       Abort
End of Screen Action

    Once data entry on the screen has been completed, the program presents the user with
a chance to visually review the data entered on the current screen before the  selected
model is run. As shown in Figure 17, the only active keyboard commands are highlighted
at the bottom of the screen:

    F2  - Edit the current screen
    F9  - Return to previous screen
    F10 - Proceed to next screen
    Esc  - Abort current scenario and return to primary selection window
Field Sensitive Help

    The help facility (see Section 5.0) can be accessed by pressing the Fl key from any of
the selection windows or data entry fields.  After pressing the Fl key a window with help
text will appear to further define or clarify the current data entry field. The user can then
                                       20

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scroll up or down through the help text and view help for other data fields. The chemical
parameter data entry fields will access help for that data field. Then after exiting the help
window, the main menu of the chemical look-up database will appear.  An example of a
help screen is shown in Figure 20.

                                  FIGURE 20.
 [Two Phase Relief Valve Discharges - Scenario 4.13;

    SOURCE PARAMETERS  - Page 1 of 3

    Enter a unique title for this data's model run:
  Title
  Enter a descriptive  TITLE for this scenario's data and model  run.
  The title will be  used for distinguishing this scenario's data
  from another  scenario's data.  A file name will be assigned by
  the program.
  •tiaStS. "Of CONGESTS
  GLOSSARY

  Percent of Liquid  Flashed
                               ACCESSING HELP SYSTEM
 List of Available KeysList of  Highlighted PhrasesUp/Down
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                                   FIGURE 21.
                    -[Chembase - Main Menu]—;	;	
                      &„  Search t.iw? Database   . I

                      B.  Add a Chemical  to Database

                      Up  Down  /Letter=Select
                      Help        Exit  ChemBase
To search the chemical database for a specific chemical (selection A), a scrollable window
appears with the available chemical names as shown in Figure 22.
                                   FIGURE 22.
                 - [Chemical Name] -
                  iiisBNu	
                  CHLORINE
              Select- hilighfced chemical          :Exit/no  selection
                          Uj? one page    ToiK/of  list;
               otte  line  Qown. ome page-   Bottom:  of  list
                       JK«Y to fiwd ch^roic-al beginning with that character
The chemical names contained in the database will be displayed in alphabetic order.  The
chemical names are selected by the point and shoot method - once the desired chemical is
highlighted, Enter is pressed to view the chemical's parameters. The highlighted bar can
be moved directly to first chemical name starting with a certain letter just by pressing that
letter key.  The 'Chemical Name' window will size itself proportionally to the number of
chemical names contained in the database up to the number of chemical names that can
fit on the screen.

   The add and search (look-up) screens are identical in appearance and are shown in
Figure 23.
                                       22

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                                   FIGURE 23.
-I view unemicajt uacaj
Chemical name: B&H2RHB
Boiling point at ambient pressure 	
Specific heat of liquid
at constant pressure 	
at constant volume 	
Specific heat of vapor
at constant pressure 	
at constant volume 	
Molecular weight 	
Latent heat of vaporization 	
Liquid density 	

	 353.1 °K

•••• : ••!:'•'"" ' cal/g-mole K
• • • • ',... ' ' . cal/g-mole °K

• • • • . cal/g-mole K
• • • • cal/g-mole °K
• • • • 78,12 g/g-mole
• • • • cal/g-mole
• • • • ,87.865 g/cu m
               Edit
Delete
Ssc  Exit View  Screen
In the look-up mode, parameters for a chemical may be updated or the chemical name and
associated chemical parameters can be deleted  from the database.  In the add mode
chemical names and their associated parameters can be appended to the chemical database.

   If the user enters the chemical database from a data entry field, a value from the
database can be returned to that field. A pointer V will appear beside the value that will
be returned. For example if the user were in a molecular weight input field, the user could
press Fl and help for that field would appear. After pressing ESC to exit the help system,
the main menu of the chemical database would appear.  The user  would select 'A. Search
the Database' and then choose the desired chemical. The chemical look-up screen  would
appear as above, but the molecular weight field would be as follows:
         Molecular weight
                     »-78.12   g/g-mole
Pressing Enter at this point would exit the chemical database and return the value 78.12
to the molecular weight input field.
                                       23

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Calculator

   When entering data,  a  calculator  is  available  on-line  to  perform  any needed
calculations. The calculator is accessed by pressing the F3 key from any data entry field.
The results of a calculation can be passed directly from the calculator to the entry field by
pressing the equals (=) key.  While in the calculator a  help screen on the calculator's
functions can be accessed by pressing the Fl key.  The calculator has several built-in
functions that include memory clear, memory store, memory recall, square, square root and
pi. An example of the calculator is shown below in Figure 24.
                                   FIGURE 24.
'I TWO fnase Kener \
SOURCE PARAMETE
Enter a unique
Jhe : Johnson Wid
FLASHED LIQUID
Enter the Peri?$
enter the boxe

Specific
ft
Storage or L
Boiling Tempsc




 Help ct













I


jnc



c












irj

f

j


)






i
i


LO

!0











!•?
3I



















t. J.J



+







/


























if unknown
%

.; . . cai/g— mole K
cal/g-mole
• .... °v
K
o „
K




creen  Abort
Model Output

    Upon completing the last screen of data entry for the scenario the F10 command is
'Run Model' and not 'Next Screen'. When the F10 key is pressed, the entered data is saved
to a file on the disk and will be accessible to the user by the Scenario Title entered at the
start of each scenario's data entry.  The selected dispersion model  then executes. The
SCREEN model will execute for 3 to 10 minutes, the RVD model for 1 to 5 minutes and
the PUFF model for 1 to 5 minutes depending on the data and the computer setup on
which TSCREEN is running.  The model output will appear on the screen in a window as
shown in Figure 25.
                                       24

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                                  FIGURE 25.

 [  MODEL OUTPUT ] - [ Top Row: 1  Left Column:  1   Length:  158 ] -----------
  1                                                                     07-11-
                                                                        12:46:
    *** SCREEN- 1.1 MODEL RUN ***
    *** VERSION DATED  88300 ***

   Continuous Particulate Stack Release from Power  Plant

   SIMPLE TERRAIN INPUTS:
      SOURCE TYPE            =    POINT
      EMISSION RATE (G/S)    =    1200.
      STACK HEIGHT (M)       =    20.00
      STK INSIDE DIAM  (M)    =     1.50
      STK EXIT VELOCITY (M/S)=     5.00
      STK GAS EXIT TEMP (K)  =   400.00
      AMBIENT AIR TEMP (K)   =   293.00
      RECEPTOR HEIGHT  (M)    =       .00
      IOPT (1=URB,2=RUR)     =     2
      BUILDING HEIGHT  (M)    =    25.00
      MIN HORIZ BLDG DIM (M) =    20.00
      MAX HORIZ BLDG DIM (M) =    45.00
                Alt, Alt,  <*->, <-*•>, , ,  ,  
             Graph    

Print Save to File Exit The model output can be scrolled line by line up or down by pressing the up or down arrow keys. The output can be put into a continuous scroll up or down by pressing the Alt - up or down arrow key combinations and stopped by pressing any key. The output can be scrolled a full screen at a time by pressing the Page Up or Page Down keys. By pressing the Home key the output display will show the top of the output listing and by pressing the End key the display will show the end of the output listing. The row number of the model output displayed in the top row of the output window is shown on the first line of the screen with the column number of the model output displayed in the first column of the output window and the total number of lines in the output listing. To get a listing of the output on a printer press the 'P' key. To avoid some common printing problems, before selecting printed output, make sure that a printer is connected to the computer, that the printer's power is on, that the printer is online and that there is plenty of paper loaded in the printer. To get a graph of the concentrations vs distances press the 'G' key. To save the output data to a file press the 'F' key and give a filename for the output data set as shown in Figure 26. 25


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                                  FIGURE 26.

 [  MODEL OUTPUT ]	[ Top Row: 1  Left Column: 1  Length: 158 ]	
  1                                                                    07-11-
                                                                       12:46:
    *** SCREEN-1.1 MODEL RUN ***
    *** VERSION DATED  88300 ***

   Continuous Particulate Stack Release from Power Plant

   SIMPLE TERRAIN INPUTS:
      SOURCE TYPE            =    POINT
      EMISSION RATE (G/S)    =    1200.
      STACK HEIGHT (M)       =    20.00
      STK INSIDE DIAM (M)    =     1.50
      STK EXIT VELOCITY (M/S)=     5.00
      STK GAS EXIT TEMP (K)  =   400.00
      AMBIENT AIR TEMP (K)   =   293.00
      RECEPTOR HEIGHT (M)    =      .00
      IOPT (1=URB,2=RUR)     =     2
      BUILDING HEIGHT (M)    =    25.00
      MIN HORIZ BLDG DIM (M) =    20.00
      MAX HORIZ BLDG DIM (M) =    45.00

              Enter a unique title for this output :  PPOUTPUT.:TXT
If the model's output has been saved, it can be reviewed using the VIEW program. To view
the saved output type VIEW < filename > from the DOS command line where filename is
a file  containing the  model output.  The model's output can be edited  with  a word
processor once it has been saved.
                                      26

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                                5.0 HELP SYSTEM

      The help system included with TSCREEN is field sensitive. As a result when the Fl
key is pressed from a data entry field, help for that field will appear for that data entry
field.  The user also has the ability to scroll up and down through the help text in order
to view help for other data fields.  A complete list of the keys available in the help system
can be displayed by pressing the Fl key.

      Within the help entries certain words will be highlighted. These highlighted words
are hyperlinks to other sections in the help text. Hyperlinks are keywords that are indexed
to point to other keywords or to a particular place in the text.  You can move to the new
section by pressing F7 to get a list of the highlighted words in the current help window.
Then, scroll  down  that list  to the hyperlink you wish to  choose and press  Enter.
Alternatively, if a mouse is available, you can move  the cursor to the highlighted word in
the help window and click the mouse's button.

      The highlighted words in the help entries are hyperlinked to definitions in the help
systems glossary. If one of these words is selected, a second help window will appear with
the glossary definition of the word selected.  From that entry in the glossary, you can scroll
up and down through other entries in the glossary. The entire help text is connected  so
that after you have scrolled above the beginning of the glossary, you can continue scrolling
through the rest of the help text.

      At  the end of each data entry help, TABLE  OF  CONTENTS and GLOSSARY are
highlighted. You can also select these hyperlinks in the same manner described above. If
TABLE OF CONTENTS is selected, you will move to the beginning of the help text where
there  are  hyperlinks to  all the  sections  in the program.  If GLOSSARY is selected, the
glossary window will appear on the screen and you will be at the beginning  of the
glossary.

      The help text is organized such that the table on contents is first followed by help
for the data entries  and  the glossary is at the end.
                                        27

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                             6.0  ERROR HANDLING

      If an error occurs while TSCREEN is running a window like the one shown in Figure
27 will appear.

                                  FIGURE 27.
                          WARNING: Error has occurred

                             !! Division by zero !!

         Make note of the scenario number and page number on the screen.
         Data entered up to the point at which the error occurred are
         saved in the file:
                                  'ERROR.OUT'
         Please save this file for use in error diagnosis.

                         Press any key to continue...
      Data saved up to the point at which the error occur will be saved in the file
ERROR.OUT.  In addition the error message will be appended to the end of this file.  Data
from that run will also be saved in the highest numbered RUN*.TSN file.  Both of these
files should be saved for error diagnosis.

      If an error occurs while a model is running the ERROR.OUT file will contain the
data that was sent to the model and the error message. The highest numbered RUN".TSN
file will contain the data you entered into TSCREEN. Save both of these files for  error
diagnosis.

      After exiting the window shown in Figure 27 you will return to the 'Initial Form of
Release' menu  shown in Figure 2.
                                      28

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                              7. 0 SYSTEM FLOW

      Figure 28 illustrates the logic flow of TSCREEN.  The help system and chemical
database can be accessed from the  scenario selection menus or from the scenario inputs.
The calculator can only be accessed from the scenario inputs.  After the scenario inputs,
either the SCREEN, RVD, or PUFF model is run. Once the model has been run, the output
is displayed and the user has the option to generate a graph of concentrations vs. distances.

                                  FIGURE 28.
             Scenario Selection Menus
                View Model Output
                                             Help System
               Graph Concentrations
Chemical Database
                                      29

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                            8.0  BACKING UP DATA

   The file BACKUP.COM that comes with DOS must be in the DOS PATH as explained
in section 2.0 GETTING STARTED.  To backup the data enter the command:

   BACKUP X:\TSCREEN\*.* A: /S

where X is the drive letter where the TSCREEN system resides. Note that it is important
to back up every time data is edited or added in case of a hard disk failure.

   The number of backup disks needed depend upon the amount of data entered into the
system. As more data is entered, more backup disks will be required to store the data.
These disks must be formatted prior to backing up the data files. Backup disks should be
labeled accordingly and stored in a safe place.

   To ward off data corruption, rotating back up disks is recommended.  Rotating backup
diskettes consists of 2 or 3  sets  of backup diskettes that are rotated when the backup
procedure is called. In using a rotating backup procedure you can minimize the possibility
of backing up bad data and having corrupt files on the system and on the backup disks.

   The BACKUP.COM program fits as much data on one disk as it is physically capable of
storing. If the program is in the middle of backing up a file it will split it and store the
remaining part of  the file  on another disk(s).  These backed up files  are  not  DOS
compatible files, therefore copy them to another disk but not to the hard disk.  The only
way these files can be used is to first restore them with the DOS RESTORE.COM program
(discussed below).  These diskettes are created for backup  purposes only and are to be
restored only when the data files on the hard disk have become damaged beyond repair.

   The command to restore the data files is:

   RESTORE A: X: /S

where  X is the  drive  letter where the  TSCREEN system resides. Note  that  the
RESTORE.COM file must be  in the DOS PATH in order to execute this program from any
prompt. This command should be used only when there has been damage done to the data
files on the hard disk!
                                      30

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                 9.0 NOTES ON COMPILING THE SOURCE CODE

      The procedure described on this page is only for those who wish to make changes
in the source code and recompile it. Only someone with experience using computers and
preferably with compilers should attempt this procedure.

      TSCREEN  is written in and compiled with Microsoft™ BASIC Version 7.1 and
Microsoft™ C Version 5.1. Four BASIC libraries were used: ProBas™ Version 4.01, ProBas
ToolKit™ Version  2.1,  and  ProBas  HyperHelp ToolKit™ Version  1.0 by Hammerly
Computer Services, Inc.  and PCX  Programmer's  Toolkit™  Version  3.5  by  Genus
Microprogramming.  One C library was used:  INGRAF™ Version 2.10 by Sutrasoft.  The
program source code is available from the SCRAM Bulletin Board phone (919) 541-5742.
Technical questions should be directed to Jawad S. Touma; Office of Air Quality Planning
and Standards; Technical Support Division; Source  Receptor Analysis Branch (MD-14);
Research Triangle Park, NC 27711, phone (919) 541-5381. The procedure for compiling
the source code is as follows:

      BASIC Version 7.1 or later, C Version 5.1  or later, ProBas™ Version 4.0 or later,
ProBas HyperHelp ToolKit™ Version  1.0 or later, ProBas ToolKit™ Version 2.1 or later,
PCX Programmer's Toolkit™ Version 3.5 or later,  and INGRAF™ Version 2.10 or later are
necessary to compile the source code.  All of the .BAS (BASIC) files and .C (C) files should
be on a hard disk with the following files:

   BASIC
      BC.EXE
      LINK.EXE
      BCL71EFR.LIB

   ProBas
      PROBAS.LIB with ToolKit routines installed
      HYPER.OBJ (Object file compiled from HYPER.BAS contained in ProBas
                  HyperHelp ToolKit™)
      STRWMENU.OBJ (Object file compiled from STRWMENU.BAS contained in
                        ProBas ToolKit™)

   PCX
      PCX_QB.LIB
                                      31

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      CL.EXE
      LINK.EXE
      MLIBCE.LIB
      SLIBCE.LIB
      [STRING.H]
      [STDIO.H]
      [STDLIB.H]
      [PROCESS.H]
      [MATH.H]
      [DOS.H]
      [IO.H]
     The files in brackets are included with the Microsoft C compiler

   INGRAF
      INGRAF.LIB
      IGEXTERN.H

   The  COMPILE.BAT,  LOPTIONO,  LOPTION1,  LOPTION2, LOPTHELP,  LOPTTS,
LOPTAVE, LOPTGRAF, LOPTGRPH, LOPTPCX, and LOPTERR files from the source code
diskette should also be present in the same directory. Note that you may have to change
the path specifications in these files as well as in the C files and the BASICS files.  Then
simply type COMPILE and compilation is automatic. The resulting program files will be
TSMAIN.EXE, VIEW.EXE, CHEMBASE.EXE, HELPSYS.EXE, TSCREEN.EXE, AVETIME.EXE,
GRAF.EXE, GRAPH.EXE, PCXHELP.EXE, and ERHANDLE.EXE.  Several other files will be
created with the .OBJ extension and can be deleted upon successful compilation.
                                    32

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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO. 2.
EPA-450/4-90-013
4. TITLE AND SUBTITLE
User's Guide to TSCREEN: A Model for Screening Toxic
Air Pollutant Concentrations
7. AUTHOR(S)
Kevin Stroupe, Calvin Thames and Steve Boone
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Pacific Environmental Services, Inc.
3708 Mayfair Street, Suite 202
Durham, N.C. 27707
12. SPONSORING AGENCY NAME AND ADDRESS
U.S. Environmental Protection Agency
Office of Air Quality Planning and Standards
Research Triangle Park, N.C. 27711
3. RECIPIENT'S ACCESSION NO.
5. REPORT DATE
August 1990
6. PERFORMING ORGANIZATION CODE
8. PERFORMING ORGANIZATION REPORT NC
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO
68-02-4464
13. TYPE OF REPORT AND PERIOD COVEREC
Final Report
14. SPONSORING AGENCY CODE
15, SUPPLEMENTARY NOTES
EPA Technical Representative: Jawad S. Touma
16. ABSTRACT
  This user's guide describes how to start,  enter/edit, use help system, back up data
  and compile the TSCREEN model.   TSCREEN is a model  for estimating ambient pollutant
  concentrations  for a  variety of release scenarios from Superfund sites and other
  sources of air  toxics releases.  This computer program implements the procedures
  developed in a  document entitled "A Workbook of Screening Techniques for Assessing
  Impacts of Toxic Air  Pollutants," EPA-450/4-88-009 and should be used in conjunction
  with this workbook.   TSCREEN has a front-end control  program that also provides,
  by use of interactive menus and data entry screens, the same steps as the workbook.
  An extensive help system is provided to guide the user.  Text edit and graphical
  display capabilities  are also provided.
17. KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS
Air Pollution
Hazardous Waste Assessment
Toxic Air Pollutants
Dense Gas Models
Air Quality Dispersion Model
Superfund
18. DISTRIBUTION STATEMENT
Release Unlimited
b. IDENTIFIERS/OPEN ENDED TERMS
Dispersion Modeling
Meteorology
Air Pollution Control
19 SECURITY CLASS iTins Repurtl
Unclassified
c. COSAT1 Held/Group
13B
21 NO OF PAGES
35
20 SECURITY CLASS iT!uspa%e) ,22. ^RICE
Unclassified
EPA Form 2220-1 (Rev. 4-77)
                     PREVIOUS EDITION ' S OBSOLETE

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